Field of the Invention
Embodiments of the present disclosure generally relate to ground fault detection and, more particularly, to a method and apparatus for detecting a ground fault.
Description of the Related Art
Solar panels, or photovoltaic (PV) modules, convert energy from sunlight received into direct current (DC). The PV modules cannot store the electrical energy they produce, so the energy must either be dispersed to an energy storage system, such as a battery or pumped hydroelectricity storage, or dispersed by a load. One option to use the energy produced is to employ one or more inverters to convert the DC current into an alternating current (AC) and couple the AC current to the commercial power grid. The power produced by such a distributed generation (DG) system can then be sold to the commercial power company.
In order to couple generated power to a commercial AC power grid, inverters must meet certain safety standards such as determining whether a fault to ground condition exists on the DC side and disabling power production if such a condition does exist. Having a ground reference at the inverter for measuring ground fault currents requires propagating the ground from the inverter back to the grid, resulting in additional wiring and therefore costs to support the ground connection.
Therefore, there is a need in the art for a method and apparatus for detecting a ground fault condition without connecting to a ground reference.